Hair straightener



FIG. 1 is a front perspective view of a hair straightener showing my new design;

FIG. 2 is a left side view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a top view thereof;

FIG. 5 is a bottom view thereof;

FIG. 6 is a front view thereof; and,

FIG. 7 is a rear view thereof.

The uneven length broken lines adjacent to the shaded region form an unclaimed boundary of the design. The even length broken line showing of the remainder of the hair straightener represent unclaimed subject matter. 

CLAIM The ornamental design for a hair straightener, as shown and described. 